As expected, Facebook is announcing a "modern messaging system" today. Mark Zuckerberg says it's not email. But it might just replace it. Get ready for your @facebook.com address.
What are the difference between Facebook messages and regular email? It incorporates emails, Facebook messages, SMS, other chat clients. Eventually VoIP may also be in play. Instead of having some chats here and some texts there, every time you talk to someone it'll be come part of a stream of information.
And while you can collect it all at an @facebook.com email address, it's not mandatory. You can redirect your Gmail messages there, for instance. And yes, an iPhone app update is coming shortly that incorporates Facebook Messages.
Notable differences from regular email? There are no subject lines, no CC or BCC. You can send a message just by hitting the Enter key. It's going to feel like chat. A lot of times, it's going to be chat.
There will also be a threading solution, which records every type of contact you've had with a person in one place. It's a one-stop conversation shop, a way to tell the full story of a conversation.
Facebook will also introduce the Social Inbox, which sorts your personal messages, prioritizing notes from friends and setting aside people you aren't as close with. This is the killer function: as a default, you'll only see messages from your friends (and friends of friends). Junk—from people who are outside of your Facebook circle—will go into a separate folder. And you can move people from one folder to the other (which is nice for those of us whose family doesn't have Facebook). You can also choose to actively bounce any email that's not from a friend.
As much as I enjoy Gmail's Priority Inbox, it can't filter nearly as effectively as Facebook can. That's the advantage of the "social graph" that Facebook can access, and why you're going to want to give this a serious look.
Zuckerberg insists that this isn't going to be a Gmail killer, and for the time being, at least, he's right. But Facebook's looking towards the future, towards a generation that's steadily and increasingly been abandoning email for instant communication. And the more we abandon email for text and chat, the more Facebook's going to be the communication hub.